A drop axle is commonly used on the front of many makes and models of vehicles, particularly in a steering application. Each drop axle has end portions, which support wheel mountings onto which wheels are mounted. It is termed a “drop” axle due to the fact that an intermediate portion, between the end portions, drops down and has a secondary axis, which is offset from and substantially parallel to a primary axis provided by the end portions.
Walking beams are used on many makes and models of vehicle to connect the axles. The beams are connected to the axles from below at their beam-ends. A suspension is mounted to the centre of the beams and serves to connect the beams and axle assembly to the vehicle frame. Front to rear torque rods are generally provided to control movement of the axle assembly during braking and acceleration. An example of a walking beam assembly is U.S. Pat. No. 5,228,718 (Kooistra 1993) currently owned and manufactured by Raydan Manufacturing Inc.
Vehicles having two drop axles are generally not equipped with walking beam assemblies. The reason for this is that the dropping down of the intermediate portion of the drop axle decreases ground clearance for the attachment of a walking beam. If any current models of walking beams were attached between two drop axles, there would not be sufficient room for a suspension between the beams and the vehicle frame. It would also restrict the articulation of the axles leaving the walking beams incapable of evenly distributing weight. These two factors would completely defeat the purpose of the walking beam.